Hepatocellular carcinoma (HCC) is the most frequent primary malignancy of the liver and is the fifth most common cancer in humans worldwide. HCC also is the fourth leading cause of cancer-related death (Parkin D M, Bray F, Ferlay J, Pisani P. Estimating the world cancer burden: Globocan 2000. Int J Cancer 2001; 94:153-156). In 1990, the World Health Organization estimated that there were about 430,000 new cases of liver cancer worldwide, and that a similar number of patients died that year as a result of this disease.
The pathogenesis of HCC has been associated with chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infections, as well as cirrhosis-inducing conditions of liver (Bruix J, et al. J Hepatol 35:421-430, 2001; Bruix J, et al. Cancer Cell 5:215-219, 2004). Accordingly, the incidence of HCC is highest in east Asian countries, such as China, Hong Kong, Taiwan, Korea, and Japan, where HBV and HCV infections are most prevalent (Bruix J, et al. Cancer Cell 5:215-219, 2004; Haskell C M. Chapter 46 Liver: Natural History, Diagnosis and Staging in “Cancer Treatment” 5th edition, W. B, Saunders Company, Philadelphia, editors: Haskell C M & Berek J S). However, the incidence of HCC in western countries is steadily increasing (Parkin D M, et al. Int J Cancer 94; 153-156, 2001). Over the past decade in the United States, HCC displayed the second highest increase in incidence, and the highest increase in death rate, of all cancers (Ann Int Med 139:817-823, 2003). Thus, in the United States and throughout the world, HCC is a major cause of mortality and morbidity, and a significant economic burden due to hospital costs and loss of work by people with HCC.
Successful control of HCC requires correct diagnosis of the disease at an early stage of disease progression. However, distinguishing small HCC tumors from other malignant or non-malignant liver diseases, including metastatic tumors, cholangiocarcinoma, focal nodular hyperplasia, dysplastic and regenerating liver nodules, using current techniques, such as imaging studies, needle core biopsy and/or fine needle aspiration, has proven to be challenging (Ferrell L D, et al. Am J Surg Pathol 17:1113-1123, 1993; Horigome H, et al. Hepato-Gatroenterology 47:1659-1662, 2000; Kalar S, et al. Arch Pathol Lab Med 131:1648-1654, 2007; Seki S, et al. Clin Cancer Res 6:3460-3473, 2000). Moreover, attempts to treat HCC therapeutically have been largely unsuccessful (Bruix J, et al. J Hepatol 35:421-430, 2001; Bruix J, et al. Cancer Cell 5:215-219, 2004; Haskell C M. Chapter 46 Liver: Natural History, Diagnosis and Staging in “Cancer Treatment” 5th edition, W. B, Saunders Company, Philadelphia, editors: Haskell C M & Berek J S; Szklaruk J, et al. AJR 180:441-453, 2003). As a result, despite active therapy, the 5-year survival rate of patients with HCC in the U.S. is only 10.5%, which is second in magnitude only to pancreatic cancer (ACS Cancer Facts & Figures (2007)). Thus, there is an urgent need to identify a more reliable marker to differentiate HCC from other liver pathologies and facilitate early detection of this disease. In addition, there is an urgent need to develop new and more-effective therapeutic agents for the treatment of HCC.